Method and apparatus for performing retro peritoneal dissection

ABSTRACT

The foregoing application describes a system and method of performing a minimally invasive surgical operation. More specifically, the invention involves the use of disposable cannula and slender dilators of variable lengths, which incorporate a source of illumination to carry light to a surgical site and video capabilities for capturing and displaying images from a CMOS or CCD camera device. According to one embodiment, fiber optics run semi-circumferentially or along walls of the cannula/dilator and terminate at about a centimeter from the distal end of the cannula/dilator, thereby preventing illumination from “bottoming out” at the floor of the incision. According to one alternate embodiment, the light fibers may be fashioned in an annulus around one or more camera chips to provide illumination and video of the surgical site. In still another embodiment, the light fibers may be replaced by light emitting diodes in a more remote light source or alternatively at the distal-tip of the CMOS or CCD camera device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/326,138, filed Apr. 20, 2010, and U.S.Provisional Patent Application Ser. No. 61/355,250 filed Jun. 16, 2010,the entire disclosures of which are hereby incorporated herein byreference.

FIELD OF THE INVENTION

This disclosure relates to human surgical procedures performedpercutaneously, and more specifically to a novel retractor,neuro-monitoring probe and progressive cannula system that enhancesillumination and visibility. The disclosure also relates to a system andmethod for providing one or more disposable or reusable camera/videodevices, including camera/video devices incorporating CCD and/or CMOStechnology.

BACKGROUND OF THE INVENTION

Surgical procedures to address illness, disease or injury vary dependingon a number of factors, including the ability of the surgeon(s) toaccess and perform the necessary procedures at the affected site. As oneexample, individuals who suffer degenerative disc disease, natural spinedeformations, a herniated disc, spine injuries or other spine disordersoften require surgery on the affected region to relieve pain or preventfurther injury to the spine and nerves. Spinal surgery may involveremoval of damaged joint tissue, insertion of a tissue implant and/orfixation of two or more adjacent vertebral bodies. These procedures areoften difficult due to the location of the spine and adjacent nerves,sensitive anatomy, etc. The surgical procedure will vary in approach andduration depending on the nature and extent of the injury.

One particular type of spinal surgery is referred to as “fusion.” Fusionof vertebral bodies involves fixation of two or more adjacent vertebrae.This procedure may be performed through introduction of rods or plates,and screws or other devices into a vertebral joint to join variousportions of a vertebra to a corresponding portion on an adjacentvertebra. Fusion may occur in the lumbar, interbody or cervical spineregion of a patient. A fusion is designed to stop and/or eliminate allmotion in the spinal segment by destruction of some or all of the jointsin that segment and further utilizing bone graft material and/or rigidimplantable fixation devices for securing the adjacent vertebrae. Byeliminating movement, back pain and further degenerative disc diseasemay be reduced or avoided. Fusion requires tools for accessing thevertebrae, such as surgical cannulae for “minimally-invasive” surgicalprocedures, and other tools for implanting the desired implant,bioactive material, etc. Such procedures often require introduction ofadditional tools to prepare a site for implantation. These tools mayinclude drills, drill guides, debridement tools, irrigation devices,vises, clamps, cannula, and other insertion/retraction tools.

Spinal surgeries may be performed by a number of different“minimally-invasive” procedures, as opposed to conventional surgicalprocedures and methods, which typically require cutting of muscles,removal of bone, and retraction of other natural elements. Withminimally invasive spinal surgery, a less destructive approach to thespine is carried out by using portals, which take advantage of anatomyand current technology to limit the damage to intervening structures.

Typically, skeletal landmarks are established fluoroscopically and asmall incision is made over the landmark(s). According to methods knownin the prior art, a series of dilators are applied until one or morecannula is placed over the anatomic structure. A microscope is thenplaced over the operative site. The microscope provides illumination andmagnification with a three dimensional view of the anatomical site.While this process provides substantial advantages relative to opensurgery, it requires the use of an operating microscope. This particularpiece of equipment is extremely expensive (most quality brands are inthe $250,000 range). The microscope is an unwieldy device requiringuncomfortable gyrations of the surgeon's back and neck in order to gainthe necessary view and is a nuisance to drape (a large, sterile plasticbag has to be placed over the eight foot tall structure). Theillumination is also difficult to direct due to the size of themicroscope.

A significant danger of performing intervertebral operations oraccessing an intervertebral space during spine surgery is that ofinadvertently contacting or damaging the para-spinal nerves, includingthe exiting nerve roots, traversing nerves and the nerves of the caudaequina. The exact location of these para-spinal nerves cannot bedetermined prior to the commencement of surgery, and therefore aredependent on a surgeon's ability to visually locate the same after theinitial incision is made. Moreover, intervertebral spaces in the spinehave other sensitive nerves disposed at locations which are not entirelypredictable prior to insertion of the surgical tool into theintervertebral area. Accordingly, the danger of pinching or damagingspinal nerves when accessing an intervertebral space has proven to bequite limiting to the methods and devices used during minimally invasivespinal surgery. In addition, as cannula are received through thepatient's back, such as when performing minimally invasive spinalsurgery, minor blood vessels are ruptured, thereby blocking thesurgeon's vision inside the intervertebral region after the cannula hasbeen inserted. Other anatomical features at a particular patient mayalso destruct the surgeon's view or make it difficult to provideillumination within the cannula.

Lateral based spinal surgery is a known alternative to conventionalsurgical procedures, and is generally referred to as a“minimally-invasive” procedure. Lateral based procedures offer theadvantages of shorter recovery times, reduced blood loss, reducedpost-operative complications, and shorter operating times thanconventional procedures and methods. For example, one surgical approachfor spinal fusion using a minimally invasive technique is known as“lumbar interbody fusion” or LIF for short. Other known examples oflateral based approaches include the Nuvasive XLIF procedure andMedtronic D-LIF System. However, these systems and methods have problemsand shortcomings, including, but not limited to, limited visualizationand lighting in the surgical area, increased risk of impinging upon thenerves of the lumbosacral plexus, and the ilioinguinal and genitofemoralnerves and the risk of devices and/or instruments becoming dislodgedduring the various procedures, among others. These problems, alone or incombination, may result in post-operative pain and discomfortexperienced by patients of lateral based spinal surgery. In someinstances, these problems require or otherwise lead to additionalsurgeries, further complicating the likelihood of recovery andsuccessful fusion.

Various devices and surgical access systems are known in the art tofacilitate minimally invasive surgical procedures while allowing for asufficiently large surgical area. These devices may include a series oftools which, when consecutively inserted, serve to gradually expand anarea, including cannula. Retractors are useful for gradually dilatingthe area of an incision or surgical opening in order to form a desiredamount of space within which various procedures may be conducted.Retractors may take the form of a single device that may be insertedinto a work area and expanded at the direction of a user, thus allowingfor the creation and maintaining of a surgical work space. Manyretractors fail to provide independent illumination sources or allow thesurgeon to visualize the path of access to the surgical site. As theseretractors are often the first (or one of the first) tools used in theprocedure, providing adequate illumination and enhancing visualizationare important to the success of the operation. Thus, there is a presentfelt need for an improved retractor with enhanced illumination thatotherwise improves the visibility for the surgeon, and for a method ofretrofitting an existing retractor with apparatus to accomplish thisobjective.

Other problems experienced in minimally invasive surgical proceduresinclude the risk of injury caused during the initial probing anddissecting of tissue between the incision and the surgical site.Typically, such probing is done using a finger or a slender dilator orother tool, which is used to navigate through the soft tissue, anatomy,and ultimately reach the desired point of access to the surgical site.During this probing, there is increased risk to injury to the lumbarplexus, particularly when the surgeon is attempting to access the lumbarspine. In addition, there is also an increased risk to the patient'sanatomy, and to undesired dissection of various anatomical featuresbetween the incision and the surgical site. This risk of injurytypically increases as the probe is inserted deeper into the body of apatient, and continues after the probe has been fully inserted andcontinuing through dilation, such as by inserting one or moreprogressive surgical cannula around the dilator proceeds. Damage to theperitoneal membrane, colon perforation, ureteral or great vessel injurycan be the result of the “blind” dissection and is major reason why thelateral, transpoas approach is not a more commonly performed surgicalprocedure. Thus, there is a deep felt need in the art to mitigate thesepotentially catastrophic complications, and to address the otherproblems associated with performing these procedures in a “blind”manner.

Typically, as these processes for accessing the surgical site are doneblind (i.e., without vision of where the probe is directed), it is notuncommon that the probing instrument(s) intersect and/or dissect thepatient's anatomy, intercept nerves, sensitive tissue, rupture arteries,etc. Thus, there is also a need for an improved tool for initiallydilating and accessing the tissue between the incision and the surgicalsite. There is a further need for an improved system and method forproviding a surgeon with visibility of this area, to assist with thenavigation through the tissue, anatomy, etc. and to provide enhancedillumination for a minimally invasive surgical procedure.

The disclosure of the invention herein addresses these and otherproblems by providing a system and method for achieving an endoscopicapproach to a surgical site, coupled with the use of a uniqueillumination and video capability. The system of the invention ispreferably achieved by incorporating a camera chip in the apparatus ofthe system, thereby obviating the need and disadvantages of theoperating microscope and other expensive and cumbersome instrumentation.These and other considerations are addressed by the present disclosurein more detail in the Summary and Detailed Description.

SUMMARY OF THE INVENTION

Incorporated by reference in their entireties are the following U.S.patents and patent applications directed generally to methods andapparatus related to spinal procedures, thus providing writtendescription support for various aspects of the present disclosure. TheU.S. patents and pending applications incorporated by reference are asfollows: U.S. Pat. No. 7,406,775 to Funk, et al.; U.S. Pat. No.7,387,643 to Michelson; U.S. Pat. No. 7,341,590 to Ferree; U.S. Pat. No.7,288,093 to Michelson; U.S. Pat. No. 7,207,992 to Ritland; U.S. Pat.No. 7,077,864 Byrd III, et al.; U.S. Pat. No. 7,025,769 to Ferree; U.S.Pat. No. 6,719,795 to Cornwall, et al.; U.S. Pat. No. 6,364,880 toMichelson; U.S. Pat. No. 6,328,738 to Suddaby; U.S. Pat. No. 6,290,724to Marino; U.S. Pat. No. 6,113,602 to Sand; U.S. Pat. No. 6,030,401 toMarino; U.S. Pat. No. 5,865,846 to Bryan, et al.; U.S. Pat. No.5,569,246 to Ojima, et al.; U.S. Pat. No. 5,527,312 to Ray; and2008/0255564 to Michelson. These references assist in explaining thecurrent state of the art for surgical instruments generally, and provideadditional written support for the various apparatus and methodsdescribed herein.

According to one particular embodiment of the present disclosure, theinvention involves the use of a disposable cannula of variable lengths,which are applied over the dilator tools. These cannulas can have avariety of shapes depending upon the surgical requirement. Ovoid,egg-shaped or round cannulas are contemplated and may further comprisean angled working edge as described in greater detail herein. Thedevices described herein are unique in that they have incorporated asource of illumination, preferably attached to the walls of the cannula,which emit light to the base of the portal and enhance illuminationwithin the cannula.

According to yet another aspect of the present disclosure, a modifiedretractor according to various embodiments is described thatincorporates illumination and/or video capabilities. The modifiedretractor cooperates with cannula described in greater detail below topermit a surgeon to avoid nerves, aberrant vessels and other anatomicalfeatures such as the kidney, ureter, peritoneal membrane, etc. Accordingto one embodiment, the retractor includes an extension or “periscope”feature that moves longitudinally along the shaft of the blade of theretractor to exclude retroperitoneal fat or other tissue that otherwiseobscures the view of the surgeon along the outer surface of the blade ofthe retractor, where one or more cannula may be mounted.

According to one embodiment of the disclosure, the illumination isprovided by way of fiber optic strands or bundles. The fiber optics canrun circumferentially or along one or more walls of the cannula, andpreferably terminate at least a centimeter from the bottom of thedevice. This prevents the illumination from “bottoming out” at the floorof the incision. Additionally, the light fibers may be fashioned in anannulus around a camera chip device to provide illumination to thesurgical site where images are being captured by the camera chip device.In still another embodiment, the light fibers may be replaced by one ormore LEDs in a remote light source or at the distal-tip of the camerachip device. The light source may come from an external device such as aheadlight lamp, or a standard-type light source commonly found inoperating rooms which plugs into an adaptor on the disposable cannula.

According to embodiments described herein, the system comprises adisposable cannula that has at least one slot through which the camerachip device(s) can be passed and inserted on a composite insert, whichpreferably fits in a tongue and groove fashion down the slot of thecannula. The camera chip device may have associated wide-angle opticsand its composite insert can be easily removed/adjusted during thecourse of the operation for cleaning or when the cannula needs to bere-directed or reoriented during the course of the surgery.

The camera chip device, which according to a preferred embodiment isbased on either CCD or CMOS technology, may have the necessaryvideo-processing circuitry onboard the camera chip device housing, orthe video-processing circuitry may be housed separately, several metersaway from the camera chip device, and connected by a cable oralternatively via wireless transmission. For further details on the typeof camera chip device according to a preferred embodiment of the presentdisclosure, applicant hereby incorporates by reference in its entiretythe disclosure of U.S. Pat. No. 6,310,642.

According to one embodiment, an apparatus and method and providedwhereby, instead of the surgeon viewing the operative site through theoculars of the microscope, the anatomy is presented on a screen in frontof him (or her) and in front of the assistant(s). Due to the camera chipdevice and associated optics housing being placed directly at theoperative site, the image collected is free from the distortions and the“field-flattening” effects found when using complex optical stackscommonly found in operating microscopes and endoscopes. This results ina significant increase in “depth-cues” and color-reproduction and inturn improves visibility. The camera technology provides a threedimensional-type picture to the surgeon with enhanced illumination, andwithout the extra costs of adding a second camera device and expensiveintra-ocular optical orientations. The costs of the microscope and itsmaintenance, plastic draping, sterility/contamination issues and surgeonfatigue are either eliminated or at least substantially reduced.

According to yet another embodiment of the present disclosure, a tool isprovided that comprises at least one CMOS or CCD video imaging device,which permits a user to view images captured by the CMOS or CCD imagingdevice of the disc space or other surgical area to be operated on. Forexample, one or more angled tools may incorporate a video insert(described in greater detail below), for capturing and viewing images ofthe intervertebral disc space during or after dissection has occurred.This may be accomplished by providing a CMOS or CCD camera device at thedistal end of the one or more angled tools, and either wirelessly orhardwire transmitting the images captured by that CMOS or CCD camera toa display. As one other example, one or more scraping or debridementtools may incorporate the video insert described in greater detailbelow, for capturing and viewing images of the intervertebral disc spaceafter and during dissection. This capacity allows for a more completeand safe disc space preparation. A more precise carpentry of the discspace allows for an increased potential for fusion and a reduction ofvertebral endplate or soft tissue injury. This may be accomplished byproviding a CMOS or CCD camera at the distal end of the one ordebridement tools, and either wirelessly or hardwire transmitting theimages captured by that CMOS or CCD camera to a display.

One having skill in the art will appreciate that the apparatus describedherein, according to various embodiments of the present disclosure, mayhave various sizes. The sizes of the various elements of embodiments ofthe present disclosure may be sized based on factors including, forexample, the anatomy of the patient, the person operating the apparatus,the surgical site location, physical features of any implanted devicerequired with the surgical procedure, including, for example, width,length and thickness, and the size of the drill or other surgical toolbeing used with the apparatus, and other factors.

According to one embodiment, the illumination and camera/videocapabilities described herein may be provided with one or more cannulahaving a shape other than round (e.g., oval, pointed, square cornered,egg-shaped etc.) and having an end (e.g., the end inserted into thepatient, distal from the user) that is angled and/or tapered and/orshaped to be ideally seated in a particular surgical site. Asymmetricalcannulas may allow visualization of the facet joint of the spine, forexample. An “egg-shaped” cross section may allow for the best view ofthe facet joint and further minimizes the medial-lateral dissection thata round cannula would require. Such shapes are specifically contemplatedfor incorporating the illumination and camera/video apparatus'sdescribed herein.

Still other aspects of the invention are directed to cannula instrumentsthat have a patient contacting end that is adjustable to assume apredetermined conformation. Thus, in one embodiment, material forms theend that comes into contact with bone, tissue, and especially as itnears nerve tissue, with such cannula end material being malleable to anextent necessary for the surgeon to mold the end such that it achievesthe desired contours or avoids particular structures encountered in anyparticular surgery. By way of example but not limitation, if a bonyoutcropping, a nerve fiber, etc. is perceived by the surgeon, thecannula tip end can be adjusted to avoid undesired contact orinterference with such tissues or structures.

In particular embodiments, the ability to adjust the geometricparameters of the cannula end may be achieved by manipulation of theother end of the instrument. For example, providing a turnable componentat the opposite end of the instrument, the shape of the other end of theinstrument (i.e. the end inserted into the patient) can be adjusted toeither expand circumference, reduce circumference, render the openingmore or less oblong, etc. In such a manner, it is possible to avoidhaving to remove the instrument or cannula from the patient's site toadjust the morphology of the instrument, thus saving time, avoidingundesired reinsertion procedures, etc.

According to another embodiment of the present disclosure, a system isprovided wherein the cannula further include one or more electricalprobes at the exit portal, which are adapted to assist the surgeon inidentifying the presence and location of nerves as the probe is advancedduring minimally-invasive surgery, thereby providing further assistanceand feedback for guiding the path of the cannula and other surgicalinstruments to be inserted into the surgical site.

An expandable tip cannula or dilator may be provided, which functionsboth as an access portal for surgery and as a system for nervesurveillance, such that the presence and relative position ofpara-spinal nerves, for example, can be detected as the expandable tipcannula is inserted through the patient's facia and musculature. Oneparticular advantage of determining the position of the lumbosacralplexus with respect to the distal tip of the cannula/dilator is that thelumbosacral plexus can be avoided or gently moved out of the surgeon'sway while inserting the cannula/dilator.

According to one embodiment, the present disclosure provides a system ofcannulas adapted to assist the surgeon in guiding the path of surgicalinstruments received into the intervertebral space, while identifyingthe presence and location of para-spinal nerves as the cannula isadvanced to a patient's intervertebral space during minimally invasivesurgery. In various aspects of the present disclosure, probes of thetype described in greater detail herein may be comprised of one or moreelectrodes powered at a low level to sense the position of a para-spinalnerve through continuous real time electromyographic monitoring.Alternatively, these electrodes can be powered at a higher level suchthat they operate to cauterize blood vessels. Safety systems ensure thatpower levels sufficient to cause cauterization are not activated if anerve is sensed to be near the electrodes at the distal end of thecannula.

According to yet another embodiment of the present disclosure, a systemis provided where the cannula or dilator further include one or moreelectrical probes at the exit portal/patient contacting end, which areadapted to assist the surgeon in identifying the presence and locationof nerves as the probe is advanced during minimally-invasive surgery,thereby providing a device for guiding the path of other surgicalinstruments to be inserted into the intervertebral space.

According to one embodiment, the present disclosure provides a system ofcannulas adapted to assist the surgeon in guiding the path of surgicalinstruments received into an intervertebral space, while identifying thepresence and location of para-spinal nerves as the cannula is advancedto a patient's intervertebral space during minimally invasive surgery.In various aspects of the present disclosure, the system of cannulas mayfurther comprise of one or more electrodes powered at a low level tosense the position of the nerves of the lumbo-sacral plexus throughcontinuous real time electromyographic monitoring. Alternatively, theseelectrodes can be powered at a higher level such that they operate tocauterize blood vessels. Safety systems ensure that power levelssufficient to cause cauterization are not activated if a nerve is sensedto be near the electrodes at the distal end of the cannula.

One having skill in the art will appreciate that embodiments of thepresent disclosure may be constructed of materials known to provide, orpredictably manufactured to provide the various aspects of the presentdisclosure. These materials may include, for example, stainless steel,titanium alloy, aluminum alloy, chromium alloy, and other metals ormetal alloys. These materials may also include, for example, PEEK,carbon fiber, ABS plastic, polyurethane, rubber, latex, syntheticrubber, and other fiber-encased resinous materials, synthetic materials,polymers, and natural materials.

One having skill in the art will appreciate that embodiments of thepresent disclosure may be controlled by means other than manualmanipulation. Embodiments of the present disclosure may be designed andshaped such that the apparatus may be controlled, for example, remotelyby an operator, remotely by an operator through a computer controller,by an operator using proportioning devices, programmatically by acomputer controller, by servo-controlled mechanisms, byhydraulically-driven mechanisms, by pneumatically-driven mechanisms orby piezoelectric actuators.

The Summary of the Invention is neither intended nor should it beconstrued as being representative of the full extent and scope of thepresent disclosure. The present disclosure is set forth in variouslevels of detail in the Summary of the Invention as well as in theattached drawings and the Detailed Description of the Invention and nolimitation as to the scope of the present disclosure is intended byeither the inclusion or non-inclusion of elements, components, etc. inthis Summary of the Invention. Additional aspects of the presentdisclosure will become more readily apparent from the DetailedDescription, particularly when taken together with the drawings.

The above-described benefits, embodiments, and/or characterizations arenot necessarily complete or exhaustive, and in particular, as to thepatentable subject matter disclosed herein. Other benefits, embodiments,and/or characterizations of the present disclosure are possibleutilizing, alone or in combination, as set forth above and/or describedin the accompanying figures and/or in the description herein below.Further details and description of embodiments of the present disclosureare provided in the Appendix A to this application.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure relates to systems and methods for accessingintervertebral space and facilitating the use of surgical tools andinserting spine implants between vertebral bodies. Those of skill in theart will recognize that the following description is merely illustrativeof the principles of the disclosure, which may be applied in variousways to provide many different alternative embodiments. This descriptionis made for illustrating the general principles of the teachings of thisdisclosure invention and is not meant to limit the inventive conceptsdisclosed herein.

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the disclosure andtogether with the general description of the disclosure given above andthe detailed description of the drawings given below, serve to explainthe principles of the disclosures.

FIG. 1 is a perspective view of a modified retractor according to oneembodiment of the present disclosure; and

FIG. 2 is another perspective view of the modified retractor of FIG. 1;

FIG. 3 is a conceptual diagram of the modified retractor of FIG. 1 witha means for providing illumination at or near the distal end of themodified retractor;

FIG. 4 is a conceptual diagram of the modified retractor of FIG. 1mating with a semi-circular cannula and having enhanced illumination forimproving visibility within the cannula;

FIG. 5 is a side sectional view of a dilator that includes aneuro-monitoring lead that extends from the body of the dilator,illumination means, and at least one other lumen for a camera deviceaccording to one embodiment of the present disclosure;

FIG. 6 shows a cross-sectional view of the dilator of FIG. 5;

FIG. 7 is a perspective view of a cannula according to a preferredembodiment of the present disclosure;

FIG. 8 is a perspective view of an interlocking cannula with the cannulaof FIG. 7;

FIG. 9 is a cross-sectional view of the cannula shown in FIG. 8;

FIG. 10 is a view of the cannula of FIG. 9 in a docked view;

FIG. 11 is a perspective view of a cannula with at least one channel forinserting an anchoring device and at least one slot for mating with anillumination and/or video insert according to one embodiment of thepresent disclosure;

FIG. 12 is a perspective view of the cannula of FIG. 11 and the cannulaof FIG. 7;

FIG. 13 is a perspective view of the cannula of FIG. 12 in a dockedview;

FIG. 14 includes a cross-sectional view of the cannula, according to onealternative embodiment, with LED illumination devices and a CMOS/CCDcamera slot, and a top plan view of the cannula according to thisembodiment;

FIG. 15 is a detailed cross-sectional view of the cannula shown in FIG.14;

FIG. 16 is a perspective view of the cannula according to one embodimentwith a hardwired CMOS/CCD camera device insert;

FIG. 17 is a detailed perspective view of the CMOS/CCD camera insertaccording to FIG. 16 with a fiber optic array;

FIG. 18 includes perspective views of a cannula, according to anotheralternative embodiment, with and without the CMOS/CCD camera insert; and

FIG. 19 is a perspective view of a dilator tool according to onealternative embodiment of the present disclosure.

It should be understood that the above-referenced drawing figures arenot necessarily to scale. In certain instances, details that are notnecessary for an understanding of the disclosure or that render otherdetails difficult to perceive may have been omitted. It should beunderstood, of course, that the disclosure is not necessarily limited tothe particular embodiments illustrated herein.

DETAILED DESCRIPTION

Various embodiments of the apparatus and methods of the presentdisclosure are described in detail below. The following patents arehereby incorporated by reference for the express purpose of describingthe technology related to the use of illumination and video capabilitiesdescribed herein, including the use of camera chips and CCD or CMOStechnology: U.S. Pat. No. 6,310,642; U.S. Pat. No. 6,275,255; U.S. Pat.No. 6,043,839; U.S. Pat. No. 5,929,901; U.S. Pat. No. 6,211,904; U.S.Pat. No. 5,986,693; and U.S. Pat. No. 7,030,904.

Referring now to FIGS. 1-4, a modified retractor according toembodiments of the present disclosure is shown, which incorporatesillumination and/or video capabilities of the nature described herein.This “Sherrill” retractor comprises a longitudinal blade, which extendslongitudinally a length sufficient for inserting into a patient toassist in retracting tissue between the incision and the surgical site,and may incorporate one more lumens internal to the blade for providingillumination means and/or CMOS or CCD video capabilities. This“Sherrill” retractor may alternatively be used, or used in connectionwith the dilator or wand described below in connection with FIGS. 5-6.Further details of this modified retractor are provided below.

FIG. 1 is a perspective view of the modified retractor 1 according toone embodiment of the present disclosure. The modified retractor 1comprises a handle 3 and a generally planar blade 5 that has a lengthsufficient to reach a variety of surgical sites. The retractor 1 mayfurther comprise one or more visual landmarks 7 along the length of theblade 5 as shown in FIGS. 1 and 2. According to one embodiment, thehandle 3 may be detachable from the blade 5 and may also besubstantially hollow for housing a power source, such as a battery, asdescribed in further detail below in connection with FIG. 3.

FIG. 2 depicts another perspective view of the modified retractor 1 ofFIG. 1. In a preferred embodiment, the blade 5 of the modified retractor(such as the one shown in FIG. 4) comprises two thin edges formed alongat least a portion of the sides of the blade 5, which are convenient foruse in attaching a semi-circular or semi-oval shaped cannula (shown inFIG. 4 as 25) by sliding the cannula over the two thin edges of theblade 5. Thus, according to one embodiment shown in FIG. 4, a cannula 25is provided with two corresponding grooves or lips 27 along the surfaceof the cannula body, and oriented to couple with the two thin edges ofthe modified retractor.

In this manner, a surgeon using the modified retractor may first insertthe retractor, retract any tissue and other anatomical features betweenthe incision and the surgical site, and then attach the cannula 25 bysliding the cannula 25 along the two thin edges in a longitudinaldirection relative to, the blade 15 of the retractor. In anotherembodiment, the two thin edges may have slightly raised surfaces orbosses for facilitating this attachment via a tongue and grooveconnection. In one embodiment, the handle 13 of the modified retractorextends in generally the same direction as the blade 15 of the modifiedretractor, or is offset from the plane of the blade by an angle lessthan 90 degrees to facilitate this interconnectivity between themodified retractor and the cannula described above.

According to one embodiment of the present disclosure, a method isdisclosed whereby the dissecting finger is followed by this modified“Sherrill” retractor, which preferably incorporates one or more lightemitting diodes 19 at its distal end as shown in FIG. 3, and a handle 13containing the LED power source. According to this method, as thesurgeon advances his blunt finger dissection of the retroperitonealspace, the Sherrill retractor 11 follows the finger with a visible pathpreventing inadvertent damage to intra- and retroperitoneal structures.The Sherrill retractor 11 is preferably modified to incorporate one ormore camera devices (such as CMOS camera chips) at its contacting endand secured within a housing for allowing safe, visual placement throughthe dissected retroperitoneal space. This technique and associatedapparatus shown in FIGS. 1-4 may be particularly useful for a surgeonattempting placement of the retractor onto the psoas muscle whileavoiding the ilioinguinal and genitofemoral nerves on the surface of themuscle.

According to one embodiment, a flexible sleeve may be fabricated to fitover the body of an existing retractor or distractor device andincorporate the lumens or channels for inserting one or more fiber opticstrands or bundles, and may also include a slot for inserting a camerainsert such as the type described above. Therefore, existing retractorsand distracters manufactured by various parties such as Medtronic andNuvasive may incorporate the concepts of the present disclosure despitehaving no prefabricated lumens or slots for accommodating the necessaryillumination and/or video capabilities discussed herein.

FIGS. 5-6 show a specific dilator or “wand” according to one preferredembodiment, which may be used for achieving the objectives describedherein. In this embodiment, the dilator or wand 29 has a generally ovoidcross-sectional shape and is sufficient in size to accommodate aplurality of lumens, through which a CMOS or CCD camera insert 31 and/orillumination means 35 such as one or more light emitting diodes may beincorporated. According to a preferred embodiment, the dilator or wand29 comprises at least one lumen 33 which extends beyond the length ofthe generally ovoid section of the dilator or wand, which may be used ina tapering configuration (and according to one alternative embodiment, atelescoping configuration) for gently probing through tissue, achievingvision (via CMOS or CCD video technology) of the anatomy through whichthe surgeon must navigate prior to securing the cannula to the surgicalsite, etc. In this embodiment, the dilator or wand 29 also comprises alumen 33 through which one or more conductive materials may be insertedfor stimulation of the various nerves of the psoas. This dilator 29 mayalso house illumination means 35, such as fiber optic strands and/or LEDdevices, for allowing a light source at the useable end of the dilatoror wand 29.

In use, this enhanced dilator 29 allows the surgeon to have directvisualization and illumination of the retroperitoneal space, and allowssimultaneous stimulation of the psoas or other spinal nerves, via one ormore electrical probes which are incorporated into one of the pluralityof lumens of the dilator 29. This dilator 29 therefore serves as aguide, which allows the surgeon to safely and securely reach thesurgical site without causing damage to any of the patient's anatomy,and continue with application of progressively larger dilators andworking cannula (including those described herein) without causinginjury to the patient.

The dilator 29 may vary in length, according to the patient and theunique anatomy presented for the surgical operation. According to apreferred embodiment, the length dilator 29 is in the range of 50-500millimeters in length, and the diameter is approximately 2-10millimeters. The material of the dilator 29 is preferably selected fromthe group consisting of aluminum, iron, titanium, steel, stainlesssteel, surgical stainless steel of the general alloy type of iron,carbon, chromium (12-20%) molybdenum (0.2-3%) and nickel (8-12%),martensitic steel, grade 316L austenitic steel, grade 316LVM austeniticsteel, grade 316 stainless steel, medical grade plastic and PEEK.

According to one embodiment of the present disclosure, the same distalend of the dilator 29 that comprises a CCD or CMOS video device 31further comprises a conductive material, which is capable oftransmitting signals, such as neurological signals to a measuring devicefor detecting one or more nerves in-between the incision and thesurgical site. This distal neuro-monitoring tip may be made of a varietyof different conductive materials, including but not limited to copper,brass, aluminum, metal alloy, inherently conductive polymers or any ofthe known polymers having a conductive filler, such as metal fillers,metal-cooled glass and/or carbon fiber fillers.

One or more CCD or CMOS camera devices 31 located at the distal end ofthe dilator 29 may be surrounded by a lens, and the lens made of aconductive glass, wherein the conductivity of the device and the lens ofthe device are accomplished in a single integrated apparatus. Accordingto a preferred embodiment, the distal end of the dilator 29 is generallyovoid in shape and provides for a compound radii, which further assistsin moving soft and often sensitive tissue away from the tip of thedilator as it is inserted into the patient. Similarly, the conductivematerial at the distal tip of the dilator 29 is preferably ovoid, andpermits material to be moved gently away from the device at isprogressed deeper into the incision.

According to various embodiments, the dilator 29 further comprises oneor more fiber optic fibers which extend longitudinally down the shaft ofthe dilator for providing illumination. According to one embodiment, theone or more strands are positioned proximate to the CCD or CMOS videodevice 31, such that the CCD or CMOS video device 31 has adequateillumination for capturing images at the distal end of the dilator 29.This illumination also allows a surgeon to achieve adequatevisualization, both with the naked eye and through images captured bythe CCD or CMOS video device 31. In an alternate embodiment, theillumination is proved by one or more LED devices adjacent the CCD orCMOS video device 31.

Referring again to the drawing figures, according to one embodiment, thedilator 29 may be comprised of a generally cylindrical body, having agenerally ovoid cross-section as shown in FIG. 6, and may incorporatemultiple lumens extending therethrough. One or more internal lumens mayincorporate the fiber optic illumination strands and/or the CCD or CMOSvideo device, while the second lumen may provide a channel for receivingsignals via the conductive material at the distal end of the dilator.This second lumen may alternately serve as a guide for wire anchors tobe positioned from the end opposite the CCD or CMOS video device, whichallow the surgeon to insert, for example, 0.0625 inch K-wire or othersuitable wire or fastening device to secure to the disc space.

According to the embodiment shown in the drawing FIGS. 5-6 andparticularly in the alternate embodiment shown in FIG. 19, theillumination and CCD or CMOS camera device may extend a distance beyondthe generally cylindrical body of the dilator, such that theillumination and video device precede the navigation of the generallycylindrical body of the dilator, thereby permitting the surgeon to seeand illuminate tissue, sensitive anatomy, etc. prior to impact by thedilator.

In use, a method of retro peritoneal dissection involves using one ormore slender video dilators to gently probe through the incision and toview the images captured by the CCD or CMOS video device located on ornear the distal end of the one or more slender dilators. As the surgeonencounters sensitive anatomical features, such as the patient'sintestine, images of those anatomical features will become apparent tothe surgeon via the display. The images of other anatomical features arealso captured by the CCD or CMOS video device during dissection andinsertion of the one or more slender dilators.

If certain anatomical features cannot be moved from the path of thedilator, the approach of the surgeon may be adjusted accordingly, andthe dilator inserted around these features to avoid undesireddissection. This in turn allows the surgeon to view the path to the discspace, achieve the desired approach and insure that any furtherinstrumentation or apparatus that are inserted through the incision donot encounter the sensitive anatomical features of the patient, andfurther insure that the cannula are properly seated adjacent the discspace.

Once the slender dilator has been inserted through the sensitive anatomyof the patient and approaches the desired surgical cite, the surgeon canfurther use the images captured from the CCD or CMOS video device tofind the desired location of the disc space where the operation willproceed, dissection of the disc space will occur, etc. According to oneembodiment, this method involves incorporating one or more cannula,which may be inserted over the video dilator, and seated on the discspace using the same path achieved by insertion of the video dilator.Additional cannula may then be placed over this initial cannula, untilthe desired access has been achieved. Once the cannula are in positionover the slender dilator, the surgeon may remove the dilator and usedirect vision through the cannula, or use the slender dilator tocontinue to view the disc space, or both.

According to varying embodiments, this dilator and cannula system allowssimultaneous illumination and video imaging of the path through whichthe surgeon must navigate to reach the surgical site. This in turnreduces the risk of unwanted dissection, unwanted exposure and damage tosurrounding nerves, soft or sensitive tissue, etc. In use, the dilatormay be further manipulated in conjunction with the Sherrill retractor(see FIG. 1), wherein this Sherrill retractor provides a narrow yet deepretracting blade, which may or may not incorporate a illuminated end,such as by an LED, which allows the surgeon to initially probe using theblade and remove the initial tissue immediately below the incision. TheSherrill retractor blade therefore provides an initial depth ofillumination and navigation, and clears a passage for further insertionof the dilator. Multiple views of the Sherrill retractor used incombination with the dilator are shown in the appended drawing FIGS.1-4.

This approach and apparatus is further advantageous in that italleviates a common problem experienced by surgeons performing minimallyinvasive surgical procedures, which is fatigue. Using this dilatorapparatus and method the surgeon is not required to position himself orherself over the cannula, or over a cumbersome or bulky microscope,which are frequently required in other surgical methods. By avoiding thepositioning of the surgeon over the patient's body, the cannula, themicroscope, etc., the surgeon is able to avoid significant discomfortand fatigue, which occurs naturally over time, particularly due to thesurgery exceeding two hours to complete, or in some cases, 8 to 10 hoursto complete. Using this method, the surgeon further avoids the necessaryprecautions required for exposure to radiographic imaging using thismethod. For example, the surgeon, by eliminating the use of x-rays andother radiographic equipment, is not required to wear a lead vest, aneck shield, a leaded glass face shield, etc. This further reduces theweight that the surgeon must bear during the operation, further reducingthe stress and fatigue on the surgeon during the procedure.

Although not shown in the enclosed drawing figures, the slender dilatormay further comprise one more mechanisms for cleaning or clearing thelens of the CMOS video camera at the distal end of the dilator.According to one embodiment, the clearing of the lens may occurmechanically, such as by a wiping mechanism, applied to a dilator suchas the one shown in FIGS. 5-6 and 19. This wiping mechanism may bemechanically operated from the opposite distal end of the slenderdilator as the one incorporating the CCD or CMOS video device, such asby a trigger mechanism. In operation, by moving the triggerlongitudinally along the axis of the dilator, the surgeon can move thewiping device across the lens of the CCD or CMOS video device, therebyclearing the lens of loose tissue, mucus, or other fluids.

According to one particular embodiment of the present disclosure, theinvention involves the use of one or more cannula of variable lengths,which according to a preferred embodiment are applied over one or moredilators. These cannulas can have a variety of shapes depending upon thesurgical requirement. Ovoid, egg-shaped or round have been described,and an angled working edge is further contemplated. The apparatus ofthis system are unique in that they have incorporated a source ofillumination built into the walls of the cannula, which carry the lightto the base of the portal of the cannula, and further incorporatecamera/video capabilities.

Attention is drawn to FIGS. 7-18. One or more cannula in a preferredembodiment are disclosed, and are generally tubular in form, with asupport wall which has an open distal end and an open proximal end. Thedistal end may be rounded so that tissues are pushed aside gently as thecannula is inserted through the patient. A bore runs the length of thecannula from the open distal end to the open proximal end, and providesaccess to the targeted spinal area for instrument insertion, andinsertion and removal of implant devices, arthroscopic devices, graftmaterials, bone cement, and other materials and devices.

A cross-sectional shape of the support wall of the bore may be round,oval, elliptical, crescent-shaped, a half-sphere or half-oval or anothersuitable shape. The cross-sectional shape has a width, which may have ameasurement in the range of about 10-50 millimeters. Preferably thewidth is in the range of about 15-35 millimeters. The open proximal endmay further comprise a plurality of grip features which allow thesurgeon to grip the cannula. The cannula may be formed of substantiallysterile material, and may further comprise biocompatible polymers,elastomers, ceramics, or aluminum or other metals. According to oneembodiment, the cannula is disposable. In another embodiment, thecannula is reusable.

One aspect of the present disclosure is providing a cannula with anincorporated illumination source that provides enhanced illumination tothe surgical site sufficient to incorporate camera/video capabilitieswith the apparatus and system. According to one particular embodiment,the illumination is provided by incorporating one or more fiber opticstrands in the tubular body of the cannula. The fiber optics can runcircumferentially or along opposite walls of the cannula and preferablyterminate at least a centimeter from the bottom of the device. The lightfibers may be fashioned in an annulus around a camera device (See FIG.17) to provide illumination to the surgical site where images are beingcaptured by the camera chip device. In still another embodiment, thelight fibers may be replaced by one or more LEDs (See FIGS. 14-16) in aremote light source or at the distal-tip of the camera chip device. Thelight source may come from an external device such as a headlight lamp,or a standard-type light source commonly found in operating rooms whichplugs into an adaptor on the disposable cannula.

Referring now in detail to FIGS. 7-13, various cannula according to oneembodiment of the system of the present disclosure are shown. In FIG. 7,a perspective view of a cannula 2 is shown having a generally circularfirst surface 4 and a generally elliptical second surface 6. About oneintersection of the first surface 4 and second surface 6 is a channel orlumen 8 for inserting one or more fastening devices, such as a screw,for securing the cannula 2 to the surgical site. The cannula 2 shown inFIG. 7 may vary in lengths and widths according to the anatomy of thepatient, the surgical site to be accessed, and other factors relating tothe surgery, including the tools or implants that are required to beinserted into the cannula 2.

Referring now to FIG. 8, the cannula 2 shown in FIG. 7 may be coupled toone or more additional cannula 12, for example, by way of a compressionfit between the two or more cannula 2, 12. As shown in FIG. 8, thesecond cannula 12 may be inserted by a compression relief 14 formedabout one distal end of the second cannula 12 that is dimensioned to fitin compression with the tubular body 10 of the first cannula 2.According to alternate embodiments, an interlocking fit may be furtheraccomplished by way of a snap fitting, a tongue and groove fitting, orother means of securing the first cannula 2 to the second cannula 12that are known in the art. In an alternative embodiment, the cannula (2,12) may be interlocked in a predetermined configuration that permits thecannula (2, 12) to expand in telescoping fashion.

Referring now to FIG. 9, the first and second cannula 2, 12 are shown ina cross-sectional view. This assembly includes at least one channel orlumen 8 for inserting at least one fastening device, such as a screw, aswell as two smaller lumens or channels 14, 16 which may be used forinserting one or more fiber optic strands/bundles for providing enhancedillumination. These channels 14, 16 may run substantially the entirelength of the second cannula 12, and may be greater or fewer in numberthan shown in FIG. 9. The objective of providing these channels 14, 16on the interior of the cannula assembly is to provide sufficientlighting to allow the surgeon to view the surgical site and complete thesurgery without visual impairment.

Referring now in detail to FIG. 10, the first and second cannula 2, 12are shown in a docked or assembled state. The second cannula 12 may varyin length to accommodate surgery taking place in various portions of thepatient's body, and according to alternate embodiments may beasymmetrical about its length, thereby providing a larger opening at oneend than the distal end which mates with the first cannula 2. Thus, inoperation, the first cannula 2 is secured by way of a fastening membersuch as a screw, and then the second cannula 12 is inserted into thefirst cannula 2. According to a preferred embodiment, one or more of thecannula 2, 12 shown in FIG. 10 may be disposable. According to alternateembodiments, the cannula 2, 12 shown in FIG. 10 may be reusable.

FIG. 11 shows a perspective view of a cannula 22 with at least one slot24 for accommodating compression or expansion of the tubular body of thecannula 22. Similar to the second cannula 12 discussed above, thiscannula may be inserted into the base cannula 2 which is secured to thesurgical site. This cannula 22 also includes channels 26, 28 forinserting one or more fiberoptic bundles for providing illumination.

Referring now to FIG. 12, the cannula 22 of FIG. 11 is shown with thecannula 2 of FIG. 7, and is oriented in a manner to permit interlockingbetween the first cannula 2 and this slotted cannula 22. FIG. 13 showsthe cannula 22 of FIG. 11 and the cannula 2 of FIG. 7 in a docked orassembled position. This docking occurs similar to that described inrelation to FIG. 8 above, such that there is a compression fit betweenthe two cannula 2, 22. In certain embodiments, the placement of theslotted cannula 22 on the base cannula 2 does not interfere with thesurgeon's ability to remove or replace the fastening member. Thisassembly therefore provides an extended cannula which includes channels26, 28 for inserting one or more fiberoptic bundles to provide adequatelighting. These channels 26, 28 may also provide a location for securingan insert which may provide video capabilities within the tubular bodyof the cannula assembly, either hardwired or wirelessly. In anotherembodiment, multiple slotted cannula, similar to cannula 22, may bejoined such that the slot(s) in a first slotted cannula aligns with theslot(s) in a second slotted cannula.

Referring now in detail to FIG. 16, a camera insert 40 which may beinserted into a slot of the cannula 12 shown in FIG. 11 is displayed inan assembled state. Accordingly, the base cannula 2 which has beensecured to the operating site is then coupled to the slotted cannula 12.Once the slotted cannula 12 is in place, a tool 45 may be used to insertthe camera insert 40 into the slot 30 as shown in FIG. 16. Subsequently,the tool 45 may be removed, or alternatively the tool 45 may incorporateelectrical leads to the insert and remain in the slot 30 during thesurgery. Additional illumination, including by one or more fiber opticstrands/bundles (not shown in FIG. 16) may also be provided toaccommodate lighting insert. According to one embodiment, the camerainsert 40 provides both video capabilities and illumination to thesurgical site. Further description of the various camera technologieswhich may be incorporated in this design shown in FIG. 16 are describedin detail herein, but expressly include CCD and CMOS technology.

According to an alternative embodiment, one or more light fibers/bundlesmay be fashioned in an annulus around the camera insert 40 to provideillumination to the surgical site. In still another embodiment, thelight fibers may be replaced by LEDs in a remote light source or at thedistal-tip of the cannula 12 or the camera insert 40. The light sourcemay come from an external device such as a headlight lamp, or astandard-type light source commonly found in operating rooms which plugsinto an adaptor on the cannula 12.

According to a preferred embodiment, the cannula described hereincomprise at least one slot through which one or more camera device(s)can be inserted on a complimentary thin plastic composite stem-shapedinsert, which preferably fits in a tongue and groove fashion along thetubular body of the cannula. The camera device(s) with associatedwide-angle optics and its composite holder can be removed during thecourse of the operation for cleaning or when the cannula needs to bere-directed during the course of the surgery. The camera device, whichaccording to a preferred embodiment is based on either CCD or CMOStechnology, may have the necessary video-processing circuitry onboardthe camera chip housing or the video-processing circuitry may be housedseveral meters away from the camera chip and connected by a cable or viawireless transmission.

Referring again the drawing figures, FIG. 14 shows two views of acannula which incorporates light emitting diode or “LED” illuminationdevices and at least one slot for incorporating a CMOS or CCD camerainsert into the cannula wall. As shown in FIG. 14, the cannula isgenerally ovoid in shape (as viewed in cross-section or in a top planview), and has at least one inwardly facing shoulder, through which oneor more LED's may be inserted or secured for providing illuminationabout the interior of the cannula. According to a preferred embodiment,the cannula further comprises at least one planar wall, which breaks thegenerally ovoid shape of the cannula, and it is about this planarsurface that the CMOS or CCD camera insert is preferably secured.

According to a preferred embodiment, the CMOS or CCD camera insert isinserted into a slot or groove or channel which is formed about oneinterior wall of the planar surface of cannula as shown in FIG. 14.Alternatively, the CMOS or CCD camera insert can be attached by othermeans, such as by using fastening devices known in the art, or byattaching magnetically, for example, by way of one or more neodymiummagnets.

According to the embodiment shown in FIG. 14, the inwardly facingshoulder creates an interior plane (as viewed in cross-section) whichaccommodates the coupling of a progressive cannula, thereby extendingthe overall length of the cannula. Thus, one or more of the progressivecannula, which may be coupled together in a telescoping arrangement, maybe disposable, reusable, etc.

FIG. 15 shows a more detailed view of the location of the LED devices,which according to a preferred embodiment are at least three in number.The LED devices are preferably spaced equidistance from one another andat opposite poles of the generally ovoid cross-sectional shape of thecannula. According to alternate embodiments, fewer or greater number ofLEDs may be provided for providing sufficient illumination within thecannula, and it is expressly understood that locations other than thoseshown in FIGS. 14-15 are understood to be compatible with the nature ofthe invention disclosed herein.

Referring again to FIG. 16, a CMOS or CCD camera insert, which may behardwired to a connector, is shown in a perspective view in relation toa progressive cannula according to one embodiment. As shown in FIG. 16,the CMOS or CCD camera insert may be inserted along the interior portionof the generally planar surface of cannula, to a certain depth of thecannula, such that it is positioned to capture images at the distal endof cannula (i.e., the end of the cannula closest to the surgical site).

As shown in FIG. 16, the distal end of the cannula may also comprise aexterior slot for securing to an anchor or guide wire, which may beaffixed to one or more anatomical features located at or adjacent thesurgical site. Alternatively, this slot may also facilitate connectionof this cannula to one or more progressive cannula, and according to oneembodiment may serve as a guide for one or more surgical syringes, suchas the type typically used for bone marrow extraction.

The connector shown in FIG. 16 may be hardwired to the CMOS or CCDcamera device, and is of a nature to connect to one or more displaymeans, such as an LCD or LED or other video display. Thus, imagescaptured by the CMOS or CCD camera device are transmitted via theconnector to the display for viewing either still or live video imagescaptured during the surgery.

Referring now to FIG. 17, a detailed perspective view of the CMOS or CCDcamera device and fiber optic array of illumination members are shown.According to this embodiment, the CMOS or CCD camera device is protectedby a housing, which is generally cylindrical and surrounds a portion ofthe CMOS or CCD camera device. At one end of the camera housing is anopening for the lens of the CMOS or CCD camera device, and also for thefiber optic array of illumination members. In this embodiment, the fiberoptic array of illumination members substantially surrounds the lens ofthe CMOS or CCD camera device. These illumination members according to apreferred embodiment are fiber optic strands, which are arranged in oneor more layers about the circumference of the lens of the CMOS or CCDcamera device. The overall size of the CMOS or CCD camera device, fiberoptic array of illumination members and camera housing are sufficientlysmall such that they do not interfere with the insertion of tools,implants, etc. in the body of the cannula and used by the surgeon duringthe surgical procedure. Other details regarding the CMOS or CCD camerainsert are provided above in connection with FIGS. 7-13.

Additional views of the CMOS or CCD camera insert and the cannulaaccording to a preferred embodiment are shown in FIG. 18. As shown inFIG. 18, the CMOS or CCD camera insert is attached to an insert whichoperates like a stem and slides longitudinally down one planar surfaceof the cannula where it engages a slot. This engagement between theinsert and the slot secures the CMOS or CCD camera device to theinterior of the cannula. The connector shown in FIG. 18 provides bothpower and the illumination necessary to operate the CMOS or CCD cameradevice, including the fiber optic array of illumination members.

Referring now to FIG. 19, a dilator assembly according to one alternateembodiment is shown. During a surgical procedure, it may be necessaryfor a initial probe, such as a slender dilator (also known as a pilotcannula) to be inserted into a small incision and used to probe thetissue between the incision and the surgical site. The pilot dilator maybe used for this purpose, and may incorporate the video and/orillumination capabilities as described in more detail above. Accordingto this alternative embodiment, the pilot dilator is approximately 2.5millimeters to 10 millimeters in diameter.

Additional dilators/cannula may be inserted beside or over the firstdilator in a progressive fashion until a sufficient pathway through thepatient's tissue and anatomy has been formed for inserting one or moreof the progressive cannula described above over these progressivedilators. By way of example but not limitation, a second dilator rangingin diameter from 7.5 millimeters to 12 5 millimeters may be placed overand around the first dilator, then a third dilator ranging in diameterfrom 10 millimeters to 15 millimeters may be placed over the seconddilator, and a fourth dilator ranging in diameter from 12.5 millimetersmay be placed over the third dilator. This step may be repeated severaltimes by the surgeon, as necessary, until an adequate sized pathway isformed for inserting the cannula over the dilator assembly withoutcausing trauma to the incision, the patient's anatomy, the surgicalsite, etc. It is expressly understood, although not depicted in FIG. 19,the video capabilities and illumination capabilities described hereinmay be incorporated with the pilot cannula and each of the first,second, third and fourth dilators described above (and any additionalprogressive dilators) for facilitating insertion, placement, and forachieving the other benefits described in the present disclosure.

According to one particular embodiment of the present disclosure, asystem is provided where the cannula/dilator tools further include oneor more electrical probes at the exit portal, which are adapted toassist the surgeon in identifying the presence and location of nerves asthe probe is advanced during minimally-invasive surgery, therebyproviding a device for guiding the path of other surgical instruments tobe inserted into the intervertebral space. For example, an expandabletip cannula may be provided, which functions both as an access portalfor spinal surgery and as a system for nerve surveillance, such that thepresence and relative position of the nerves of the lumbo-sacral plexuscan be detected as the expandable tip cannula is inserted through thepatient's fascia and musculature. One particular advantage ofdetermining the position of the nerves with respect to the distal tip ofthe cannula is that the nerves can be avoided or gently moved out of thesurgeon's way while inserting the cannula. This concept may also beincorporated in the one or more slender dilator tools described indetail herein.

According to another embodiment, the present disclosure provides asystem of cannulas/dilators adapted to assist the surgeon in guiding thepath of surgical instruments received into the intervertebral space,while identifying the presence and location of para-spinal nerves as thecannula/dilator is advanced to a patient's intervertebral space duringminimally invasive surgery. In various aspects of the presentdisclosure, the probes may be comprised of one or more electrodespowered at a low level to sense the position of the nerves of thelumbo-sacral plexus through continuous real time electromyographicmonitoring. Alternatively, these electrodes can be powered at a higherlevel such that they operate to cauterize blood vessels. Safety systemsensure that power levels sufficient to cause cauterization are notactivated if a nerve is sensed to be near the electrodes at the distalend of the cannula/dilator.

The system according to one embodiment of the present disclosureincludes providing illumination and video capability with a cannulahaving a shape other than round (e.g., oval, pointed, square cornered,etc.) and having an end (e.g., the end inserted into the patient, distalfrom the user) that is angled and/or shaped to be ideally seated in asurgical site. Asymmetrical cannulas may allow visualization of thefacet joint, and an “egg-shaped” cross section may allow for the bestview of the facet joint and minimizes the medial-lateral dissection thata round cannula would require.

Still other aspects of the invention are directed to cannula instrumentsthat have a patient contacting end that is adjustable to assume apredetermined conformation. Thus, in one embodiment, material forms thetip end that comes into contact with bone, tissue, and especially as itnears nerve tissue, with such cannula end material being malleable to anextent necessary for the surgeon to mold the end conformation such thatit achieves desired avoidance of particular structures encountered inany particular surgery. Thus, if a bony outcropping, a nerve fiber, etc.is perceived by the surgeon, the cannula tip end can be adjusted toavoid undesired contact or interference with such tissues or structures.In particular embodiments, the ability to adjust the geometricparameters of the tip end is achieved by manipulation of the other endof the instrument. For example, providing a turnable component at theopposite end of the instrument, the shape of the other end of theinstrument (i.e. the end inserted into the patient) can be adjusted toexpand circumference, reduce circumference, render the opening more orless oblong, etc. In such a manner, it is possible to avoid having toremove the instrument or cannula from the patient's site to adjust themorphology of the instrument or cannula operating end, thus saving time,avoiding undesired reinsertion procedures, etc.

Certain embodiments of the surgical cannula, which may be used inconjunction with certain aspects of the present disclosure, includecannula having a bottom opening that is angled oblique to the topopening. These cannuale may be in correspondingly larger or smaller formfactors so that they may become nested within one another forfacilitating insertion in the patient. The cannula may have anelliptical cross-section. In one embodiment, the ellipse has a width ofabout 20 millimeters in its major axis, and a width of about 16millimeters in its minor axis. It will be appreciated that the cannulacross-section may be of a different size and have a different shapeincluding, for example, an oval, a rectangle, a square, a rhombus, atrapezoid, a parallelogram, a polygon and a generally oblong shape suchas an egg or football shape. As will be appreciated by one having skillin the art, the cross-sectional shape of the cannula permits the user toemploy instruments in the cannula that require movement or manipulationin one direction, preferably along the major axis, but to a lesserextent in the other direction. The oblong shape of the cannula wouldpermit, for example, rasps and curettes to be manipulated and used in ajoint in a minimally invasive fashion. Similarly, other tools can bemanipulated and used in a joint at any angle relative to the shaft ofthe tool. One having skill in the art will appreciate that the specificdimensional requirements of the cannula will vary based on the length ofthe cannula, and the items or tools being inserted therein.

As will be appreciated, the cannula provides access to adjacent facetsof two adjacent vertebrae. The oval or elliptical shape of the cannula,however, allows the procedure to be performed in a minimally invasivefashion by reducing the incision required to gain access to the surgicalsite and the reducing the tissue exposed during the procedure. Anotheradvantage provided by certain embodiments of the cannula of the presentdisclosure is that it provides optimal access to a surgical site thatmay have anatomy or bone features that make it desirable to have, forexample, an angled and/or curved end to the cannula. One having skill inthe art will further appreciate that an ideally shaped cannula willallow the user to more safely and reliably access the surgical site andwill reduce the risk of injury to the surrounding tissue.

Various dilators may be used (in connection with the cannula of thesystem described above) having various sizes, various lengths andcross-sectional areas. The dilators, like the cannula described above,may have an oval or elliptical shape. According to a preferredembodiment, one or more dilators may be used to dilate the muscle orother tissue of the patient to access the surgical site. According to apreferred embodiment, a first slender dilator is used to probe throughthe muscle or other tissue and to locate the desired vertebrae. Oncethat first slender dilator is seated, additional dilators may beinserted around the previously seated dilator until the desiredcircumference through the muscle or other tissue is achieved. In thisfashion, the first slender dilator serves as a radiographic marker, andestablishes the path for subsequent dilators of greater circumferencethan the first slender dilator. This serves to reduce ischemic injury tothe patient and reduces the time necessary to locate and access thedesired vertebrae. The first slender dilator has a sufficientcircumference to be easily viewed by x-ray or other imaging technologywhen seating the dilator on the desired vertebrae. The dilators arevariable in length, preferably ranging from 3-14 cm.

Once the dilators have been used to dilate the muscle tissue surroundingthe path to the desired vertebrae, a cannula may be inserted into theinterior circumference of the dilators. The cannula according to apreferred embodiment is ovoid in shape to permit dissection from caudadto cephalad (as opposed to from medial to lateral) and furtheraccommodate dissection about the facet joint. As with the dilators, thecannula may be variable in length, ranging preferably from 3-10 cm, toaccommodate varying depths from skin to bone. As mentioned above, thecross-sectional geometry of the cannula is preferably ovoid in shape,and in a preferred embodiment the major diametrical axis of the cannulais about 20 mm, and the minor diametrical axis of the cannula is about16 mm.

Varying embodiments of the cannula described herein may further comprisean angled or sloped surface at one distal end of the cannula foraccommodating access and viewing of an implant site that is not directlybelow the incision. By way of example but not limitation, a surgeon mayuse one or more of the cannula described herein in conjunction with thedilators described herein to probe through the muscle or other tissueusing an angled approach, thereby allowing access to a specificvertebrae either above or below the vertebrae directly below theincision. Once the dilators have been used to clear a path through themuscle or other tissue at an angled approach, the angled cannula may beinserted with the angled or sloped surface oriented so that the angledor sloped surface rests near horizontally against the vertebrae. Thesecannula assist the access and visibility of additional vertebrae withoutrequiring additional incisions, and further permits securing fasteningdevices such as screws using an angled approach.

As with the other cannula described above, the cross-sectional shape ofthe angled cannula is preferably ovoid in shape, and the entirelongitudinal length of the angled cannula may be slightly greater thanthe other cannula described herein. According to another embodiment ofthe present disclosure, a system is provided where the cannula furtherinclude one or more electrical probes at the exit portal, which areadapted to assist the surgeon in identifying the presence and locationof nerves as the probe is advanced during minimally-invasive surgery,thereby providing a device for guiding the path of other surgicalinstruments to be inserted into the intervertebral space.

An expandable tip cannula may be provided, which functions both as anaccess portal for spinal surgery and as a system for nerve surveillance,such that the presence and relative position of para-spinal nerves canbe detected as the expandable tip cannula is inserted through thepatient's facia and musculature. An advantage of determining theposition of the para-spinal nerve with respect to the distal tip of thecannula in particular is that the para-spinal nerve can be avoided orgently moved out of the surgeon's way while inserting the cannula.

Accordingly, the present disclosure provides a system of cannulasadapted to assist the surgeon in guiding the path of surgicalinstruments received into the intervertebral space, while identifyingthe presence and location of para-spinal nerves as the cannula isadvanced to a patient's intervertebral space during minimally invasivesurgery. In various aspects of the present disclosure, the probes may becomprised of one or more electrodes powered at a low level to sense theposition of a para-spinal nerve through continuous real timeelectromyographic monitoring. Alternatively, these electrodes can bepowered at a higher level such that they operate to cauterize bloodvessels. Safety systems ensure that power levels sufficient to causecauterization are not activated if a nerve is sensed to be near theelectrodes at the distal end of the cannula.

The present disclosure is also directed to an angled tool for use inperforming spinal surgery procedures that includes illumination and/orvideo capabilities. According to a preferred embodiment, the angled toolis comprised of a longitudinal shaft, and has a first or operating endand a second or working end. The shaft is preferably tubular and has abore running through the length of the angular tool suitable forreceiving an insert. The insert further comprises CMOS or CCD videoimaging device(s), which permit a user to view images captured by the atleast one CMOS or CCD imaging device. According to one embodiment theinsert and CMOS/CCD video imaging device(s) are disposable. In anotherembodiment they are reusable. In yet another embodiment, the angled toolfurther comprises one or more illumination devices arranged in anannulus around the one or more CMOS or CCD video imaging devices toenhance illumination at the surgical site.

In use, by providing one or more CMOS or CCD video imaging devices(which according to one embodiment further comprise at least onewireless transmitter for transmitting data wirelessly to at least onedisplay) and illumination surrounding the video imaging devices, thesurgeon has the ability to view and illuminate the patient operatingsite and/or the interior of the surgical cannula with the angled tool,in addition to any illumination that is provided by the cannula.

According to yet another embodiment of the present disclosure, a tool(other than the angled tool described above) is provided that comprisesat least one CMOS or CCD video imaging device, which permits a user toview images captured by the CMOS or CCD imaging device of the disc spaceor other surgical area to be operated on. For example, one or morespecula, curettes, awls, blades, scrapers, or other surgical tools mayincorporate the video insert described in greater detail below, forcapturing and viewing images of the surgical site after dissection hasoccurred. This may be accomplished by providing a CMOS or CCD camera atthe distal end of the one or more tools, and either wirelessly orhardwire transmitting the images captured by that CMOS or CCD camera toa display.

According to another embodiment of the present disclosure, a tool isprovided that comprises at least one CMOS or CCD video imaging device,which permits a user to view images captured by the CMOS or CCD imagingdevice of the disc space or other surgical area to be operated on. Forexample, one or more disc debridement tools may incorporate the videoinsert described in greater detail below, for capturing and viewingimages of the intervertebral disc space after and during dissection.This capacity allows for a more complete and safe disc spacepreparation. A more precise carpentry of the disc space allows for anincreased potential for fusion and a reduction of vertebral endplate orsoft tissue injury. This may be accomplished by providing a CMOS or CCDcamera at the distal end of the one or debridement tools, and eitherwirelessly or hardwire transmitting the images captured by that CMOS orCCD camera to a display.

Accordingly, the methods disclosed herein provide a surgeon viewing theoperative site, instead of through the oculars of the microscope, butrather with the ability to view the patient's anatomy by presenting theimages of the surgical site on a video screen or other display in frontof him (or her) and in front of any assistant(s), consulting surgeons,hospital staff, etc. Due to the camera chip device and associated opticsbeing placed directly at or immediately adjacent the operative site, theimage collected is free from the distortions and the “field-flattening”effect commonly associated with complex optical stacks commonly used inoperating microscopes and endoscopes. These novel apparatus and surgicalmethods result in a significant increase in “depth-cues” andcolor-reproduction. The camera device technology (preferably CCD orCMOS) provides a three dimensional-type picture to the surgeon with allnecessary illumination and without the extra costs of adding a secondcamera and expensive intra-ocular optical orientations. The costs of themicroscope and its maintenance, plastic draping, sterility/contaminationissues and surgeon fatigue are either eliminated or substantiallyreduced.

A variety of other apparatus and methods may be employed in conjunctionwith the various aspects described herein to achieve fusion withoutdeparting from the spirit of the invention, such as the followingapparatus and methods hereby incorporated by reference in theirentireties: U.S. Patent Publication Nos. 2010/0137690 to Miles, et al.;2009/0299411 to Laskowitz, et al.; 2009/0299412 to Marino; 2009/0299477to Clayton, et al.; 2009/0275995 to Truckai, et al.; 2009/0287262 toBertagnoli; and U.S. Pat. No. 7,621,955 to Goble, et al. Accordingly,additional apparatus, such as a retractor or distractor may incorporatethe use of fiberoptic bundles and/or camera inserts described inrelation to FIGS. 6-8 above. In particular, according to one embodimentof the present disclosure, a retractor device may incorporate one ormore camera inserts along the shaft of the retractor similar to thecamera insert described in relation to FIG. 16 above. Also, one or morefiberoptic bundles may be integrated with the insert, or alternativelyrun along independent lumens or channels along the arms of the retractoror distractor device.

While various embodiment of the present disclosure have been describedin detail, it is apparent that modifications and alterations of thoseembodiments will occur to those skilled in the art. However, it is to beexpressly understood that such modifications and alterations are withinthe scope and spirit of the present disclosure, as set forth in thefollowing claims.

The foregoing discussion of the disclosure has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the disclosure to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of thedisclosure are grouped together in one or more embodiments for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimed disclosurerequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Thus, the followingclaims are hereby incorporated into this Detailed Description, with eachclaim standing on its own as a separate preferred embodiment of thedisclosure.

Moreover, though the present disclosure has included description of oneor more embodiments and certain variations and modifications, othervariations and modifications are within the scope of the disclosure,e.g. the use of disposable components comprising some or all of theapparatus described herein, as may be within the skill and knowledge ofthose in the art, after understanding the present disclosure. It isintended to obtain rights which include alternative embodiments to theextent permitted, including alternate, interchangeable and/or equivalentstructures, functions, ranges or steps to those claimed, whether or notsuch alternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

1. A cannula comprising: A first or proximal end and a second or distalend and a generally tubular body therebetween; a bore through thegenerally tubular body of the cannula extending from the first end tothe second end; a camera insert comprising one or more CMOS or CCDcamera devices; wherein the cannula further comprises at least one slotabout a surface of the bore of the cannula for receiving the camerainsert within the at least one slot of the cannula; and wherein thecannula includes at least one first channel for inserting one or morefastening devices and at least one second channel for inserting one ormore illumination devices.
 2. The cannula according to claim 1 whereinthe cannula may be coupled to a second cannula to extend the effectivelength of the coupled cannula.
 3. The cannula according to claim 2wherein the second cannula is attached to the first cannula by acompression relief formed about the first end of the second cannulawhich is dimensioned to fit in compression with the second end of thefirst cannula.
 4. The cannula according to claim 2 wherein the secondcannula varies in length to accommodate surgery in various portions of apatient's body.
 5. The cannula according to claim 2 wherein the secondcannula is asymmetrical about its length.
 6. The cannula according toclaim 1 wherein the one or more CMOS or CCD camera devices furthercomprise wide-angle optics suitable for providing a three dimensionalimage on an associated display.
 7. The cannula according to claim 1wherein the camera insert is comprised of a thin, generally stem-shapedplastic composite insert that is received within the at least one slotin a tongue and groove fashion.
 8. The cannula according to claim 1wherein the camera insert is attached to a surface of the bore of thecannula magnetically.
 9. The cannula according to claim 1 wherein thecannula has a asymmetrical, ovoid, egg-shaped, crescent-shaped,half-sphere, half-oval round cross-sectional shape.
 10. The cannulaaccording to claim 1 wherein the one or more CMOS or CCD devices furthercomprises at least one wireless transmitter for transmitting imagescaptured by the one or more CMOS or CCD devices to a display.
 11. Thecannula according to claim 1 wherein the cannula has a width in therange of about 15-35 millimeters.
 12. The cannula according to claim 1wherein the cannula is formed of substantially sterile material, and mayfurther comprise biocompatible polymers, elastomers, ceramics, aluminumor other metals
 13. The cannula according to claim 1 wherein the secondend of the cannula is adjustable to a desired conformation.
 14. Thecannula according to claim 1 wherein the second end of the cannulafurther comprises at least one exterior slot for securing to an anchoror guide wire for affixing the cannula to one or more anatomicalfeatures of a patient.
 15. The cannula according to claim 1 furthercomprising one or more electrical probes at or adjacent the second endof the cannula for identifying the presence and location of nerves inthe patient.
 16. The cannula of claim 15 wherein the probes may becomprised of one or more electrodes powered at a low level to sense theposition of a para-spinal nerve through electromyographic monitoring.17. The cannula according to claim 1 further comprising an expandabletip at the second end of the cannula for detecting the presence andrelative position of para-spinal nerves.
 18. The cannula according toclaim 1 wherein the one or more illumination devices are comprised offiber optic strands or bundles.
 19. The cannula according to claim 1wherein the one or more illumination devices are arrangedcircumferentially along one or more walls of the cannula.
 20. Thecannula according to claim 1 wherein the one or more illuminationdevices terminate at least a centimeter from the second end of thecannula.
 21. The cannula according to claim 1 wherein the one or moreillumination devices are arranged in an annulus around the one or moreCMOS or CCD camera devices to enhance illumination at the surgical site.22. The cannula according to claim 1 wherein the one or moreillumination devices are comprised of one or more light emitting diodes.23. The cannula according to claim 1 wherein the at least one secondchannel for inserting one or more illumination devices existssubstantially the entire length of the cannula.
 24. The cannulaaccording to claim 1 wherein the one or more illumination devices arecomprised of fiber optic strands or bundles for transmitting light. 25.A surgical tool comprising: a shaft connecting a operating end of thetool with a working end of the tool; a disposable insert that isattachable to the shaft of the tool; the disposable insert furthercomprising at least one CMOS or CCD video imaging device, which permitsa user to view images captured by the at least one CMOS or CCD imagingdevice; wherein the at least one CMOS or CCD video imaging devicefurther comprises at least one wireless transmitter for transmittingdata wirelessly to at least one display for displaying images capturedby the at least one CMOS or CCD camera device.
 26. The surgical toolaccording to claim 25 further comprising one or more illuminationdevices arranged in an annulus around the one or more CMOS or CCD videoimaging devices to enhance illumination at the surgical site.
 27. Adilator comprising: at least one lumen extending further than the lengthof the dilator; a plurality of fiber optic strands and/or light emittingdiode devices coupled to the dilator; one or more electrical probes atthe distal end of the dilator which are connected to electrical leads atthe opposite end of the dilator; wherein the one or more electricalprobes are provided to assist the surgeon in identifying the presenceand location of nerves as the dilator is advanced within a patient'sbody and for establishing a path for subsequent surgical instruments;wherein the plurality of fiber optic strands and/or light emitting diodedevices illuminate the area immediately surrounding the distal end ofthe dilator for enhancing vision of the anatomy through which thedilator is inserted.
 28. The dilator according to claim 27 furthercomprising at least one CMOS or CCD video imaging device at or near thedistal end of the dilator for capturing photographic images of thepatient's anatomy and the surgical site.
 29. The dilator according toclaim 27 having a diameter in the range of approximately 2.5 millimetersto 10 millimeters.
 30. The dilator according to claim 27 wherein thematerial of the dilator is preferably selected from the group consistingof aluminum, iron, titanium, steel, stainless steel, surgical stainlesssteel of the general alloy type of iron, carbon, chromium (12-20%)molybdenum (0.2-3%) and nickel (8-12%), martensitic steel, grade 316Laustenitic steel, grade 316LVM austenitic steel, grade 316 stainlesssteel, medical grade plastic and PEEK.
 31. The dilator according toclaim 27 having a length in the range of 50-500 millimeters.